2-amino-3-aroyl-benzo[β]thiophenes and methods for preparing and using same to produce 6-hydroxy-2-(4-hydroxyphenyl)-3-[4-(2-aminoethoxy)-benzoyl]benzo[β]thiophenes

Abstract

A group of 2-amino-3-aroyl-benzo[β]thiophenes are prepared by treating an aldehyde with an anion of dimethylamino thioformamide, cyclizing the α-hydroxy thioamide, and subsequently acylating the benzo[β]thiophene to yield the 2-amino-3-aryl derivative. These compounds may be treated with suitable phenyl Grignard reagents, and after deprotection, yield 6 -hydroxy-2-(4-hydroxyphenyl )-3-[4-(2 -piperidinoethoxy)benzoyl]benzo[β]thiophene.

What is claimed is: 
     
       1. A method of using a compound of formula (A) ##STR8## to prepare a compound of the formula ##STR9## or the pharmaceutically acceptable salts thereof; wherein R is C 1  -C 6  alkyl; R" is C 1  -C 6  alkyl, amino C 1  -C 6  alkyl, or a group of the formula --(CH 2 ) n  NR 1  R 2 , wherein n is 1 to 4, and R 1  and R 2  are independently C 1  -C 6  alkyl, or combine to form C 4  -C 6  polymethylene or --(CH 2 ) 2  O(CH 2 ) 2  --; and   R 3  and R 4  are independently C 1  -C 6  alkyl or combine to form C 4  -C 6  polymethylene; comprising acylating a compound of the formula (A) with an acylating agent of the formula ##STR10## wherein R 5  is bromo, iodo, chloro, or a group forming an active ester.     
     
     
       2. A process according to claim 1, wherein R" is --(CH 2 ) n  NR 1  R 2 , and R 5  is bromo, chloro or iodo, and the reaction is carried out in the presence of a protic acid. 
     
     
       3. A process according to claim 2, wherein the protic acid is hydrochloric acid. 
     
     
       4. A process according to claim 3, wherein the acylating agent is 4-(2-piperidinoethoxy)benzoyl chloride hydrochloride.